javascript JS ES6语法

Posted 2021-05-03

{
  "name": "es6",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "babel src -d dist"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/cli": "^7.4.4",
    "@babel/core": "^7.4.5",
    "@babel/preset-env": "^7.4.5"
  }
}

// ES6 syntax

//let test = "Hello World";

// ES5 syntax

"use strict";

var test = "Hello World";


//classes
"use strict";

//create class
class User {
  constructor(username, email, password) {
    this.username = username;
    this.email = email;
    this.password = password;
  }

  //create static method
  static countUsers() {
    console.log("There are 50 users");
  }

  register() {
    console.log(this.username + " is registered!");
  }
}

let niweera = new User("Niweera", "[e-mail]", "srilanka");

//niweera.register();

//User.countUsers();

// inheritance 
class Member extends User {
  constructor(username, email, password, memberPackage) {
    super(username, email, password);
    this.package = memberPackage;
  }

  getPackage() {
    console.log(this.username + " is subscribed to " + this.package);
  }
}

let Niweera = new Member(
  "Niweera2",
  "[e-mail]",
  "srilanka",
  "Premium Package"
);

//Niweera.getPackage();


console.log(Number.isNaN('string'));